Rapid diagnosis of faults in hot runner multi-point redundant temperature measurement requires a four-step linkage: real-time data comparison, AI anomaly identification, system response testing, and on-site tool verification. This enables minute-level problem location, especially crucial in the high-temperature and high-humidity environment of Wuhan, where automated early warning mechanisms are essential.
1. Real-time Data Comparison (Rapid Initial Judgment)
Primary/Backup Temperature Difference Exceeds Limits: If the difference in readings between the primary and backup sensors at the same location is consistently >2℃ for more than 3 seconds, it is determined to be drift or failure.
Adjacent Measurement Point Anomalies: If the temperature difference between two points in the manifold area exceeds 1.5℃, it indicates localized overheating or coking.
Environmental Parameter Exceeds Limits: If the humidity inside the temperature control chamber is >80%RH or the temperature is >55℃, it can easily cause signal distortion, requiring the triggering of a moisture-proof alarm.
2. AI and PHM System Anomaly Identification (Precise Location)
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Slow temperature shift > 0.5℃/h (no process change) |
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Sudden temperature jump > 5℃/s during non-start/stop phases |
Initiate filter self-test |
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Loop resistance change > 10% |
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Practical Value: A medical company used AI diagnosis to provide early warnings of 78% of sensor aging failures 30 days in advance, avoiding mass scrap.
3. System Response Function Test (Verifying Fault Tolerance)
Redundancy Switching Test: Simulate a main sensor disconnection; the system should automatically switch to the backup channel and trigger an alarm within 0.5 seconds.
Safety Degradation Test: Disconnect AI communication; the system should seamlessly switch to PID control, with temperature fluctuation <= ±1.0℃.
Filtering Effectiveness Verification: Inject simulated noise to confirm that the 5Hz low-pass filter effectively suppresses glitches.
Engineering Standard: Switching response time < 0.5 seconds and temperature control accuracy <= ±1.0℃ after degradation are considered合格 (qualified).
4. On-site Tool Assistance Verification (Final Confirmation)
<3℃.
Multimeter Circuit Resistance Check: The normal thermocouple circuit resistance should be between 2~10Ω; exceeding this range indicates a circuit fault.
Nitrogen Pressure Check: The purging module pressure should be maintained between 0.2~0.4MPa to ensure effective moisture protection.
Operational Recommendation: Perform a quick comparison during each shift's inspection to establish a closed-loop record.
